When a top-secret unmanned spacecraft disintegrates on re-entry, its mysterious military payload crash-lands in the crocodile habitat of a place called Adventure Land, a combination water park, amusement land and world famous crocodile exhibit. Following its pre-programmed instructions, the payload – a next-generation nanotech-based combat drone – finds a host in the form of the park’s prize twenty-foot Australian Saltwater crocodile, Stella. She is the largest Saltwater croc in captivity. Immediately upon infecting its host, the drone payload’s nanobots begin to transform Stella from an organic, living creature into a lethal killing machine with only a single directive: Survival!

Before Chief Zoo Keeper Tim Duffy and reptile biologist Jane Spencer are able to figure out what’s going on, they find the park taken over by the government team responsible for the secret project. As the crocodile continues to transform, it escapes the crocodile exhibit and enters the water park, running amok, killing dozens of patrons. The park is evacuated, but a handful of teens are trapped behind – including among them, Duffy’s estranged son.

Duffy and Jane set out to rescue Duffy’s son while the government team and military personnel scramble to stop the rapidly evolving croc but nothing works. After their best efforts fail, the now fully-evolved ROBOCROC escapes the park and rampages further forcing a massive military deployment to stop it.

Still following its prime directive: RoboCroc enters the city sewer system. With time running out, only Duffy has the knowledge and experience that will allow him to get close enough to the croc to destroy it. In a desperate gambit, Duffy enters the sewer system armed with his knowledge of crocodile behavior and a tactical Electromagnetic Pulse Generator (EMP)...